Dengue virus (DENV) is the most important arboviral cause of morbidity and mortality throughout the world. There are currently 2.5 billion people living in dengue endemic regions with roughly 100 million annual cases of dengue fever and hundreds of thousands of cases of dengue hemorrhagic fever and dengue shock syndrome (Gubler, Clin. Microbiol. Rev. 11:480-496, 1998). No vaccines are currently commercially available against any of the four DENV serotypes (DENV 1-4), though several vaccines are currently in development or clinical trials. DENV vaccine production is hampered by the fact that neutralizing antibodies to one serotype do not effectively neutralize the remaining DENV serotypes (Halstead and O'Rourke, J. Exp. Med. 146:201-217, 1977). In fact, low levels of these antibodies may actually increase the risk for more severe disease during secondary infection due to a phenomenon known as antibody-mediated enhancement, which occurs when antibodies against one DENV serotype bind in a non-neutralizing manner to DENV particles of another serotype. This binding allows increased infection of Fc receptor-bearing cells, such as macrophages, which can change the infection profile of the virus or cause a release of chemokines leading to dengue hemorrhagic fever or dengue shock syndrome (Halstead and O'Rourke, J. Exp. Med. 146:201-217, 1977).